High precision Thick-Film load cell for dynamic force measurement

The application of load cells in industry generally requires good basic materials and accurate performance in a wide range of environments. Differences exist in manufacturing technologies, intended application, performance and cost; however, hysteresis, frequency response and creep can be a common source of errors in standard strain gauge cells. In this paper, we present a small structure based on piezoresistive effect, implemented in Thick-Film Technology (TFT) on 96% alumina substrate, working as load cell with high resonance frequency and low creep effects. The analytic model has been verified by using simulation based on finite element methods (FEM), resulting in satisfactory agreement. Based on a figure of merit (the product of the sensitivity and the square of the resonant frequency), optimized design rules are obtained for the sensors of various measure-ranges from 1 N to 10 N.